Monitoring glutathione dynamics in DNA replication (S-phase) using a two-photon reversible ratiometric fluorescent probe

The redox regulator glutathione (GSH) migrates to the nucleus to give a safeguard to DNA replication in the S-phase. The fluctuation of GSH dynamics in the cell cycle process may help to understand cancerogenesis or other abnormalities in DNA replication. For the first time, we attempted to track the time-dependent S-phase change using the newly developed ratiometric fluorescent probe Nu-GSH. This probe is highly chemoselective towards glutathione and shows an emission intensity shift from 515 nm to 455 nm. It has shown fluorescence reversibility from blue to green channels while scavenging reactive oxygen species H2O2. Both ratiometric fluorescence images and FACS analysis have provided quantitative information on the GSH levels in the nucleoli during DNA replication in the S-phase. Furthermore, GSH fluctuation reciprocated the decay of the S-phase on a time scale. Additionally, its two-photon ability guaranteed its capability to study GSH dynamics in live cells/tissues noninvasively. We envision that the probe Nu-GSH can be used to get high-throughput quantitative information on glutathione dynamics and give an opportunity to monitor its perturbation during the course of cell division.

Automated summary

The redox regulator glutathione (GSH) moves to the nucleus in the S-phase to protect DNA replication. Understanding the fluctuation of GSH during the cell cycle could provide insights into cancerogenesis and DNA replication abnormalities. The newly developed ratiometric fluorescent probe Nu-GSH was used for the first time to track time-dependent changes in the S-phase. This probe selectively detects GSH levels and showed reversible fluorescence from blue to green channels. It can provide quantitative information on GSH levels during DNA replication in the S-phase, and its two-photon ability allows noninvasive study of GSH dynamics in live cells/tissues.